It's a bit like video rendering - anything which requires data transfer back and forth kills performance, but you can sometimes keep things on the CPU a bit further down the pipe before transferring to the GPU and executing the rest of the pipeline on the GPU.
It's unlikely that you would ever want to do pixel rendering on CPU if you had any kind of GPU available, but CPUs can be pretty good at vertex processing. The classic scenario for this is a high end CPU paired with IGP, which is not that unusual.
I am very excited about this fusion stuff. Am I correct in my analysis that this can create some quite powerful small devices? Think graphics power comparing to top of the line GPU's now along with some nice strong CPU all in an mini-ITX form factor. Actually being able to play decent games on a tiny media center running linux
Well, fusion doesn't magically solve the heat problem. Try cramming a high-end 6-core and a 5890 into a single package, then try keeping it cool without liquid nitrogen. Doesn't work so well.
There will be several fusion chips with different tradeoffs between CPU and GPU power. It'd make sense to start with the models with low-end GPUs: it's enough for office work and HTPCs (assuming UVD works), so it's probably the configuration that's expected to sell best. More models can be delivered later to suit different needs.
Well, fusion doesn't magically solve the heat problem.
Not to mention it shares the same serial access memory and does the Fusion CPU also get its own framebuffer, crtc and port connectors, or... ? Because in that case you still have to have a seperate (partial) VGA and so it would only benifit OpenCL(-ish stuff) (for now).
Dynamic load balancing, we already have that, it's called SLI
No, this is a smidge different and hasn't even really been done yet. Larabee MIGHT have brought the start of that sort of thing to the picture, but sadly it's not going to be hitting the market as a discrete GPU, now is it?
... in any case compare it against an intel crappy igp
btw push 28 fps cpu only is quite an achievement
I think it could be interesting to compare this software driver with an intel IGP as it may be the #1 client for this kind of driver.
I personnally own a 9800 GT and will never think about using this software driver (and for any Nvidia/Ati solution); but on M/B with intel integrated video, for me, it make sense to compare it with any kind of intel dedicated drivers (open/closed source) or other software solution like Mesa.
Hope it will come with the next Mesa soft. vs LLVMpipe bench.